Display device

ABSTRACT

According to one embodiment, a display device includes a first drain electrode, a first insulating film which is organic, a first metal electrode in contact with the first drain electrode in a first through-hole of the first insulating film, a second insulating film which is organic, a first transparent electrode in contact with the first metal electrode in a second through-hole of the second insulating film and formed of a transparent conductive material, a third insulating film which is inorganic, a pixel electrode in contact with the first transparent electrode in a third through-hole of the third insulating film and a metal wire located between the first insulating film and the second insulating film and formed of a material identical to that of the first metal electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2018-020114, filed Feb. 7, 2018, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

In recent years, various types of display devices containing a touchsensor built therein are proposed. For example, such a display device isdisclosed, that when a plurality of electrodes formed in the displaypanel are in a touch-sensing mode, they function as sensor electrodes,whereas when in a display mode, they function as common electrodes. Asthe touch-sensing mode, either a mutual capacitance mode or aself-capacitance mode is applied. In the touch-sensing mode, sensing isperformed by applying touch drive voltage to a sensor electrode througha signal line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing an appearance of a display device of eachof the first to third embodiments.

FIG. 2 is a plan view showing a configuration example of a touch sensor.

FIG. 3 is a plan view showing a sensor electrode and a pixel shown inFIG. 2.

FIG. 4 is a diagram showing a basic structure and an equivalent circuitof the pixel.

FIG. 5 is a plan view showing an example of layout of the pixels.

FIG. 6 is a plan view showing an example of the pixel shown in FIG. 5.

FIG. 7 is a cross-sectional view of a first substrate taken along lineA-B in FIG. 6.

FIG. 8 is a cross-sectional view showing a display panel PNL taken alongline C-D in FIG. 6.

FIG. 9 is a detailed plan view showing a vicinity of a bridge portion inthe pixel layout shown in FIG. 5.

FIG. 10 is a plan view showing positions of a light-shielding layer,metallic wiring lines, a first metal electrode, and a second metalelectrode, which correspond to the pixel layout shown in FIG. 9.

FIG. 11 is a cross-sectional view of the first substrate taken alongline E-F in FIG. 10.

FIG. 12 is a cross-sectional view showing the display panel taken alongline G-H in FIG. 1.

FIG. 13 is a plan view showing a position of a groove portion shown inFIG. 12.

FIG. 14 is a cross section showing a modified example of a display panelaccording to the second embodiment shown in FIG. 12.

FIG. 15 is a cross section showing a modified example of the displaypanel according to the second embodiment shown in FIG. 12.

FIG. 16 is an enlarged view of a region I and a region J shown in FIG.13.

FIG. 17 is a plan view showing a comparative example of a terminalportion of the sensor wiring shown in FIG. 2.

FIG. 18 is a cross-sectional view of the first substrate taken alongline K-M in FIG. 17.

FIG. 19 is a plan view showing a terminal portion according to the thirdembodiment.

FIG. 20 is a cross-sectional view of the first substrate taken alongline N-O in FIG. 19.

FIG. 21 is a plan view showing a comparative example of a peripheralwire in the region U in FIG. 16.

FIG. 22 is a cross-sectional view of the first substrate SUB1 takenalong line P-Q in FIG. 21.

FIG. 23 is a plan view showing the region U of the peripheral wireaccording to the third embodiment.

FIG. 24 is a cross-sectional view of the first substrate taken alongline R-S in FIG. 23.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprises aswitching element comprising a first drain electrode, a first insulatingfilm comprising a first through-hole penetrating to the first drainelectrode and formed of an organic insulating material, a first metalelectrode in contact with the first drain electrode in the firstthrough-hole and formed of a metal material, a second insulating filmlocated on the first insulating film, comprising a second through-holepenetrating to the first metal electrode, and formed of an organicinsulating material, a first transparent electrode in contact with thefirst metal electrode in the second through-hole and formed of atransparent conductive material, a third insulating film located on thesecond insulating film, including a third through-hole penetrating tothe first transparent electrode and formed of an inorganic insulatingmaterial, a pixel electrode located on the third insulating film and incontact with the first transparent electrode in the third through-holeand a metal wire located between the first insulating film and thesecond insulating film and formed of a material identical to that of thefirst metal electrode.

The embodiments will be described hereinafter with reference to theaccompanying drawings. Note that the disclosure is presented for thesake of exemplification, and any modification and variation conceivedwithin the scope and spirit of the invention by a person having ordinaryskill in the art are naturally encompassed in the scope of invention ofthe present application. In addition, in some cases, in order to makethe description clearer, the widths, thicknesses, shapes, etc., of therespective parts are schematically illustrated in the drawings andcompared to the actual modes. However, the schematic illustration ismerely an example, and adds no restrictions to the interpretation of theinvention. In addition, in the specification and drawings, thestructural elements, which have functions identical or similar to thefunctions described in connection with preceding drawings, are denotedby like reference numbers, and an overlapping detailed descriptionthereof is omitted unless otherwise necessary.

First, a display device DSP of each of the first to third embodimentswill be described in detail. In the first to third embodiments, a liquidcrystal display device is explained as an example of the display device.

FIG. 1 is a plan view showing an appearance of a display device DSP ofeach of the first to third embodiments.

For example, a first direction X, a second direction Y and a thirddirection Z are orthogonal to each other, but they may cross each otherat an angle other than 90°. The first direction X and the seconddirection Y correspond to a direction parallel to the main surface ofthe substrate which constitutes the display device DSP, and the thirddirection Z corresponds to a thickness direction of the display deviceDSP. In this specification, the direction towards a distal end an arrowindicating the third direction Z is referred to as “above” (or merely“up”), and the direction towards opposite from the distal end of thearrow is referred to as “below” (or merely “down”). Further, anobservation position where the display device DSP is observed is set onan distal end side of the arrow which indicates the third direction Z,and plan view is defined as a view from this observation position towardan X-Y plane defined by the first direction X and the second directionY.

Here, a plan view of the display device DSP in the X-Y plane is shown.The display device DSP comprises a display panel PNL, a flexible printedcircuit 1, an IC chip 2 and a circuit board 3.

The display panel PNL is a liquid crystal display panel, which comprisesa first substrate SUB1, a second substrate SUB2, a sealing material SE,a light-shielding layer BM, spacers SP1 to SP4 and a liquid crystallayer LC, which will be described later. The display panel PNL includesa display area DA which displays images and a frame-like non-displayarea NDA which surrounds the display area DA. The second substrate SUB2opposes the first substrate SUB1. The first substrate SUB1 includes amounting portion MT extending in the second direction Y further from thesecond substrate SUB2.

The sealing material SE is provided in the non-display area NDA so as toadhere the first substrate SUB1 and the second substrate SUB2 to eachother. The light-shielding layer BM is located in the non-display areaNDA. The sealing material SE is provided in a position overlapping thelight-shielding layer BM in plan view. In FIG. 1, the region where thesealing material SE is provided and the region where the light-shieldinglayer BM is provided are illustrated by slashes different from eachother and the region where the sealing material SE and the lightshielding layer BM overlap each other is illustrated by cross-hatching.The light-shielding layer BM is provided on the second substrate SUB2.

The spacers SP1 to SP4 are all located in the non-display area NDA. Thespacer SP1 is located in the outermost circumference of the displaypanel PNL. The spacer SP2 is located on a display area DA side withrespect to the spacer SP1. The spacers SP1 and SP2 overlap the sealingmaterial SE. The spacers SP3 and SP4 are located on the display area DAside with respect to the sealing material SE. The spacers SP1 to SP4 areformed, for example, on the second substrate SUB2, but they may beprovided on the first substrate SUB1.

The display area DA is located on an inner side surrounded by thelight-shielding layer BM. The display area DA comprises, for example, aplurality of pixels PX arranged in a matrix along the first direction Xand the second direction Y.

The flexible printed circuit 1 is mounted on the mounting portion MA,and is connected to the circuit board 3. The IC chip 2 is mounted on theflexible printed circuit 1. Note that the IC chip 2 may be mounted onthe mounting portion MA. The IC chip 1 comprises a built-in displaydriver DD, which outputs signals necessary to display images in adisplay mode for displaying images. Moreover, in the exampleillustrated, the IC chip 2 contains a built-in touch controller TC whichcontrols a touch sensing mode detecting approaching or contact of anobject to the display device DSP. In the figures, the IC chip 2 isindicated by an alternate long and short dash line, whereas the displaydriver DD and the touch controller TC are indicated by dotted lines.

The display panel PNL of this embodiment may be any of a transmissivetype comprising a transmissive display function which displays images byselectively transmitting light from a rear surface side of the firstsubstrate SUB1, a reflective type comprising a reflective displayfunction which displays images by selectively reflecting light from afront surface side of the second substrate SUB2 and a trans-reflectivetype comprising both of the transmissive display function and thereflective display function.

An explanation of the detailed structure of the display panel PNL isomitted here, but the display panel PNL may have a structure providedfor a display mode which uses a lateral electric field along a mainsurface of the substrate, a display mode which uses a vertical electricfield along a normal of the main surface of the substrate, a displaymode which uses an inclined electric field inclined in an obliquedirection to the main surface of the substrate, and also a display modewhich uses the lateral electric field, the vertical electric field andthe inclined electric field in an appropriate combination. Here, themain surface of the substrate is a surface parallel to the X-Y planedefined by the first direction X and the second direction Y.

FIG. 2 is a plan view showing a configuration example of a touch sensorTS. Here, a self-capacitive touch sensor TS will be described, but thetouch sensor TS may be of a mutual capacitive mode.

The touch sensor TS comprises a plurality of sensor electrodes Rx (Rx1,Rx2, . . . ) arranged in a matrix and a plurality of sensor wiring linesL (L1, L2 . . . ). The plurality of sensor electrodes Rx are located inthe display area DA and arranged in the matrix along the first directionX and the second direction Y. One sensor electrode Rx constitutes onesensor block B. A sensor block B is the minimum unit in which touchsensing can be performed. The plurality of sensor wiring lines L, in thedisplay area DA, each extend along the second direction Y, and arearranged along the first direction X. Each of the sensor wiring lines Lis provided in the position overlapping, for example, a respectivesignal line S, which will be described later. Moreover, each of thesensor wiring lines L is drawn to the non-display area NDA, and iselectrically connected to the IC chip 2 via the flexible printed circuit1. The sensor wiring lines L each comprise a terminal portion T in thenon-display area NDA.

Here, the relationship between sensor wiring lines L1 to L3 arrangedalong the first direction X and sensor electrodes Rx1 to Rx3 arrangedalong in the second direction Y will be focused. The sensor wiring lineL1 overlaps the sensor electrodes Rx1 to Rx3, and is electricallyconnected to the sensor electrode Rx1.

The sensor wiring line L2 overlaps the sensor electrodes Rx2 and Rx3,and is electrically connected to the sensor electrode Rx2. A dummywiring line D20 is provided to be spaced from the sensor wiring line L2.The dummy wiring line D20 overlaps the sensor electrode Rx1, and iselectrically connected to the sensor electrode Rx1. The sensor wiringline L2 and the dummy wiring line D20 are located on the same signalline.

The sensor wiring line L3 overlaps the sensor electrode Rx3, and iselectrically connected to the sensor electrode Rx3. A dummy wiring lineD31 is provided to overlap the sensor electrode Rx1, and is electricallyconnected to the sensor electrode Rx1. A dummy wiring line D32 isprovided to be spaced from the dummy wiring line D31 and the sensorwiring line L3. The dummy wiring line D32 overlaps the sensor electrodeRx2, and is electrically connected to the sensor electrode Rx2. Thesensor wiring line L3 and the dummy wiring lines D31 and D32 are locatedon the same signal line.

In the touch sensing mode, the touch controller TC applies a touch drivevoltage to the sensor wiring lines L. Thus, the touch drive voltage isapplied to the sensor electrodes Rx, and sensing by the sensorelectrodes Rx is carried out. A sensor signal corresponding to theresult of the sensing by the sensor electrodes Rx is output to the touchcontroller TC via the sensor wiring lines L. The touch controller TC oran external host detects whether there is an object approaching orcontacting the display device DSP and position coordinates of the objectbased on the sensing signal.

In the display mode, the sensor electrodes Rx function as a commonelectrode CE to which a common voltage (Vcom) is applied. The commonvoltage is applied via the sensor wiring lines L from a voltage feedingportion contained in the display driver DD, for example.

FIG. 3 is a plan view showing a sensor electrode Rx shown in FIG. 2 andpixels PX. In FIG. 3, a direction intersecting the second direction Ycounter-clockwise at an acute angle is defined as a direction D1,whereas a direction intersecting the second direction Y clockwise at anacute angle is defined as a direction D2. Note that an angle θ1 madebetween the second direction Y and direction D1 is substantially thesame as an angle θ2 made between the second direction Y and thedirection D2.

One sensor electrode SE is disposed over a plurality of pixels PX. Inthe example illustrated, those of the pixels PX which are located inodd-numbered lines along the second direction Y each extend along thedirection D1. On the other hand, those of the pixels PX which arelocated in even-numbered lines along the second direction Y each extendalong the direction D2. Here, one pixel PX indicates the minimum unitwhich can be individually controlled according to a pixel signal, and itmay be called a sub-pixel. Moreover, the minimum unit for realizingcolor display may be called a main pixel MP. The main pixel isconfigured to comprise a plurality of sub-pixels PX which exhibitdifferent colors. For example, a min pixel MP comprises, as sub-pixelsPX, a red pixel displaying red, a green pixel displaying green and ablue pixel displaying blue. Note that the main pixel MP may comprise awhite pixel displaying white.

For example, in one sensor electrode Rx, sixty to seventy main pixels MPare arranged along the first direction X, and sixty to seventy mainpixels MP are arranged along the second direction.

FIG. 4 is a view illustrating a basic configuration and an equivalentcircuit of a pixel PX.

A plurality of scanning lines G are connected to a scanning line drivecircuit GD. A plurality of signal lines S are connected to a signal linedrive circuit SD. The scanning lines G and the signal lines S may notextend linearly, but part of the lines may be bent. For example, thesignal lines S extend along the second direction Y even if they arepartially bent.

One common electrode CE is provided in each sensor block B. The commonelectrode CE is connected to a voltage supply portion CD of a commonvoltage (Vcom), and is disposed over a plurality of pixels PX. Moreover,the common electrodes CE are connected also to the touch controller TCas described above, and form the sensor electrodes Rx to which the touchdrive voltage is applied in the touch sensing mode.

Each pixel PX comprises a switching element SW, a pixel electrode PE, acommon electrode CE, a liquid crystal layer LC and the like. Theswitching element SW is constituted by, for example, a thin-filmtransistor (TFT) and is electrically connected to the respectivescanning line G and the respective signal line S. The scanning line G isconnected to the switching elements SW of the respective pixels PXarranged in the first direction X. The signal line S is connected to theswitching elements SW of the respective pixels PX arranged in the seconddirection Y. The pixel electrodes PE are electrically connected to therespective switching elements SW. Each pixel electrode PE opposes therespective common electrode CE, and drives the liquid crystal layer LCby an electric field produced between the pixel electrode PE and thecommon electrode CE. A storage capacitor CS is formed between, forexample, an electrode of the same potential as that of the commonelectrode CE and an electrode of the same potential as that of the pixelelectrode PE.

FIG. 5 is a plan view showing an example of layout of pixels.

The scanning lines G1 to G3 each extend linearly along the firstdirection X, and are arranged at intervals along the second direction Y.The signal lines S1 to S4 extend substantially along the seconddirection Y, and are arranged at intervals along the first direction X.

The pixel electrodes PE1 and PE2 are disposed between the scanning linesG1 and G2. The pixel electrodes PE1 and PE2 are arranged along the firstdirection X. The pixel electrodes PE3 and PE4 are disposed between thescanning lines G2 and G3. The pixel electrodes PE3 and PE4 are arrangedalong the first direction X. The pixel electrodes PE1 and PE3 aredisposed between the signal lines S1 and S2, and the pixel electrodesPE2 and PE4 are disposed between the signal lines S2 and S3.

The pixel electrodes PE1 and PE2 comprise strip electrodes Pa1 and Pa2,respectively, extending along the direction D1. The pixel electrodes PE3and PE4 comprise strip electrodes Pa3 and Pa4, respectively, extendingalong the direction D2. In the example illustrated, the number of eachtype of the strip electrodes Pa1 to Pa4 is two, but it may be one orthree or more.

A common electrode (first common electrode) CE1 is disposed over pixelsPX1 and PX2. A common electrode (second common electrode) CE2 isdisposed over pixels PX3 and PX4. The common electrodes CE1 and CE2 arearranged along the second direction Y. The common electrodes CE1 and CE2are contained in one sensor electrode Rx shown in FIG. 2. The commonelectrode CE1 overlaps the scanning line G1 and the signal lines S1 toS3. The pixel electrodes PE1 and PE2 overlap the common electrode CE1.The common electrode CE2 overlaps the scanning line G3 and the signallines S1 to S3. The pixel electrodes PE3 and PE4 overlap the commonelectrode CE2. In the example illustrated, the scanning line G2 arelocated between the common electrodes CE1 and CE2.

A bridge portion BR is equivalent to a region indicated with slash inthe figure. The bridge portion BR is located between the commonelectrode CE1 and the common electrode CE2 and overlaps the signal lineS2. The bridge portion BR is formed to be integrated with the commonelectrode CE1 and the common electrode CE2 into one body, andelectrically connects the common electrode CE1 and the common electrodeCE2 to each other. The bridge portion BR is contained in the sensorelectrode Rx as in the case of the common electrode CE1 and the commonelectrode CE2.

FIG. 4 is a plan view showing an example of the pixel PX shown in FIG.5. Here, the main part will be described while focusing on the pixel PX1surrounded by the scanning lines G1 and G2 and the signal lines S1 andS2 shown in FIG. 5.

The switching element SW is electrically connected to the scanning lineG2 and the signal line S2. The switching element SW comprises asemiconductor layer SC and a drain electrode (first drain electrode)DE1.

The semiconductor layer SC is disposed so that one part thereof overlapsthe signal line S2 and the other parts extends between the signal linesS1 and S2 to form substantially a U shape. The semiconductor layer SCintersects the scanning line G2 in the position where it overlaps thesignal line S2 and intersects the scanning line G2 also between thesignal lines S1 and S2. In the scanning line G2, the region overlappingthe semiconductor layer SC functions as the gate electrodes GE1 and GE2.That is, in the example illustrated, the switching element SW has adouble-gate structure. The semiconductor layer SC is electricallyconnected by its one end portion SCA to the signal line S2 via athrough-hole CH1, and by its other end portion SCB, electricallyconnected to the drain electrode DE1 via a through-hole CH2.

The drain electrode DE1 is formed into an island-like shape, and isdisposed between the signal line S1 and the signal line S2. Note that inthe switching element SW, the drain electrode DE1 may be referred to asa source electrode.

The pixel electrode PE1 comprises a base BS1 integrated with theplurality of strip electrodes Pa1. The base BS1 overlaps the drainelectrode DE1, and is electrically connected to the drain electrode DE1.A connecting portion between the pixel electrode PE1 and the switchingelement SW will be described later.

FIG. 7 is a cross-sectional view of the first substrate SUB1 taken alongline A-B shown in FIG. 6. The first substrate SUB1 comprises aninsulating substrate 10, insulating films 11 to 16, a semiconductorlayer SC, a scanning line G2, a signal line S2, a metal wire ML2, acommon electrode CE1, a bridge portion BR, an alignment film AL1 and thelike.

The insulating substrate 10 is a light transmissive substrate such as aglass substrate or a flexible resin substrate. The insulating film 11 islocated on the insulating substrate 10. The semiconductor layer SC islocated on the insulating film 11, and is covered by an insulating film12. The semiconductor layer SC is formed of, for example,polycrystalline silicon, but may be formed of amorphous silicon or anoxide semiconductor.

The gate electrode GE1, which is a part of the scanning line G2, islocated on the insulating film 12, and is covered by the insulating film13. Note that the other scanning lines which are not illustrated arelocated in the same layer as that of the scanning line G2. The scanningline G2 is formed of a metal material such as aluminum (Al), titanium(Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper (Cu) orchromium (Cr), or an alloy of any combination of these metal materials,and it may be of a single- or multi-layer structure. For example, thescanning line G2 is formed from a molybdenum-tungsten alloy.

The signal line S2 is located on the insulating film 13 and is coveredby an insulating film (first insulating film) 14. Note that the othersignal lines which are not illustrated are located in the same layer asthat of the signal line S2. The signal line S2 is formed of a metalmaterial of those listed above or an alloy of any combination thereof,and it may be of a single- or multi-layer structure. For example, thesignal line S2 is a stacked layered body in which the first layercontaining titanium (Ti), the second layer containing aluminum (Al) andthe third layer containing titanium (Ti) are stacked in this order. Thesignal line S2 is in contact with the semiconductor layer SC via athrough-hole CH11 which penetrates the second insulating film 12 and thethird insulating film 13.

The metal wire ML2 is located on the insulating film 14, and is coveredby the insulating film (second insulating film) 15. The metal wire ML2is formed of a metal material of those listed above or an alloy of anycombination thereof, and it may be of a single- or multi-layerstructure. For example, the metal wire ML2 is a layered body in whichthe first layer containing titanium (Ti), the second layer containingaluminum (Al) and the third layer containing titanium (Ti), or the firstlayer containing molybdenum (Mo), the second layer containing aluminum(Al) and the third layer containing molybdenum (Mo) are stacked in thisorder.

The common electrode CE1 and the bridge portion BR are located on theinsulating film 15, and are covered by the insulating film (thirdinsulating film) 16. The common electrode CE and the bridge portion BRare transparent electrodes each formed of a transparent conductivematerial such as indium tin oxide (ITO) or indium zinc oxide (IZO). Thecommon electrode CE1 is in contact with the metallic wire ML2 via athrough-hole CH3 which penetrates the insulating film 15. The alignmentfilm AL1 is located on the insulating film 16.

The insulating films 11 to 13 and the insulating film 16 are inorganicinsulating films each formed from an inorganic insulating material suchas a silicon oxide, silicon nitride or silicon oxynitride, and they maybe of a single- or multi-layer structure. The insulating films 14 and 15are organic insulating films each formed of an organic insulatingmaterial, for example, an acrylic resin.

As described above, the common electrode CE1 functions as a sensorelectrode Rx and a metal wire ML2 functions as a sensor wire Lelectrically connected to the sensor electrode Rx.

FIG. 8 is a cross-sectional view showing the display panel PNL seenalong line C-D in FIG. 6. The example illustrated is the case where adisplay mode using a lateral electric field is applied.

In the first substrate SUB1, the signal lines S1 and S2 are located onthe insulating film 13, and are covered by the insulating film 14. Themetal wires ML1 and ML2 are located immediately above the signal linesS1 and S2, respectively. The pixel electrode PE1 is disposed on theinsulating film 16 and is covered by the alignment film AL1. The pixelelectrode PE is a transparent electrode formed of a transparent,electrically conductive material such as ITO or IZO.

The second substrate SUB2 comprises a second insulating substrate 20, alight-shielding layer BM, a color filter CF, an overcoat layer OC, analignment film AL2 and the like.

As in the case of the insulating substrate 10, the insulating substrate20 is a light transmissive substrate such as a glass substrate or aresin substrate. The light-shielding layer BM and the color filter CFare located on a side of the insulating substrate 20, which oppose thefirst substrate SUB1. The color filter CF is disposed at a positionopposing the pixel electrode PE1, and partially overlaps thelight-shielding layer BM. The color filter CF includes a red colorfilter CFR, a green color filter CFG and a blue color filter CFB. Theovercoat layer OC covers the color filter CF. The overcoat layer OC isformed of a transparent resin material. The alignment film AL2 coversthe overcoat layer OC. The alignment film AL1 and the alignment film AL2are formed of, for example, a material which exhibits horizontalalignment properties.

The first substrate SUB1 and the second substrate

SUB2 described above are disposed such that the alignment film AL1 andthe alignment film AL2 oppose each other. The first substrate SUB1 andthe second substrate SUB2 are adhered to each other with a predeterminedcell gap formed therebetween. The liquid crystal layer LC is heldbetween the alignment film AL1 and the alignment film AL2. The liquidcrystal layer LQ contains liquid crystal molecules LM. The liquidcrystal layer LC is formed from a positive type (positive dielectricconstant anisotropy) or a negative type (negative dielectric constantanisotropy) liquid crystal material.

An optical element OD1 including a polarizer PL1 is adhered to theinsulating substrate 10. An optical element OD2 including a polarizerPL2 is adhered onto the insulating substrate 20. Note that the opticalelement OD1 and the optical element OD2 may comprise a retardation film,a scattering layer, an antireflective layer or the like when necessary.

In the display panel PNL with such a configuration, the liquid crystalmolecules LM are initially aligned in a predetermined direction betweenthe alignment film AL1 and the alignment film AL2 in an OFF state inwhich an electric field is not formed between the pixel electrode PE andthe common electrode CE. In the OFF state as such, light irradiated froman illumination device IL towards the display panel PNL is absorbed bythe optical element OD1 and the optical element OD2, thus creating darkdisplay. On the other hand, in the ON state in which an electric fieldis formed between the pixel electrode PE and the common electrode CE,the liquid crystal molecules LM is aligned by the electric field in adirection different the direction in the initial alignment, and thedirection of alignment is controlled by the electric field. In the ONstate as such, part of the light from the illumination device IL passesthrough the optical element OD1 and the optical element OD2, thuscreating bright display.

Next, the display device DSP according to the first embodiment will bedescribed in detail.

FIG. 9 is a detailed plan view showing the vicinity of the bridgeportion BR in the pixel layout in FIG. 5. The pixel PX1 comprises apixel electrode PE1, a drain electrode DE1, a first metal electrode ME1and a first transparent electrode TE1. The first metal electrode ME1 andthe first transparent electrode TE1 overlap the base BS1 and the drainelectrode DE1 to form a connection portion CN1 which electricallyconnects the pixel electrode PE1 and the drain electrode DE1 to eachother. The pixel PX2 comprises a pixel electrode PE2, a drain electrode(second drain electrode) DE2, a second metal electrode ME2 and a secondtransparent electrode TE2. The drain electrodes DE1 and DE2 are arrangedalong the first direction X. The second metal electrode ME2 and thesecond transparent electrode TE2 overlap the base BS2 and the drainelectrode DE2 to form a connection portion CN2 which electricallyconnects the pixel electrode PE2 and the drain electrode DE2 to eachother.

As will be described later, the common electrodes CE1 and CE2, the firsttransparent electrode TE1, the second transparent electrode TE2 and thebridge portion BR are disposed in the same layer. The first transparentelectrode TE1 and the second transparent electrode TE2 are arrangedalong the first direction X between the common electrode CE1 and thecommon electrode CE2. The bridge portion BR is located between the firsttransparent electrode TE1 and the second transparent electrode TE2.

The metal wires ML1 to ML3 overlap the signal lines S1 to S3,respectively. The metal wire ML2 comprises a line portion LP and apedestal portion 100 in a position overlapping the bridge portion BR.The line portion LP has a width W1. The pedestal portion 100 has a widthW2. The width W2 is greater than the width W1. The metal wire ML2 iselectrically connected to the bridge portion BR in the pedestal portion100. That is, the pedestal portion 100 is in contact with the bridgeportion BR in the through-hole which overlaps the pedestal portion 100.The pedestal portion 100 is formed to be broad so as to secure theregion to be in contact with the bridge portion BR. The metal electrodeML2 is electrically connected to the common electrodes CE1 and CE2 viathe bridge portion BR.

FIG. 10 is a plan view showing positions of light-shielding layer BM,the metal wires ML1 to ML3, the first metal electrode ME1 and the secondmetal electrode ME2, which correspond to the pixel layout in FIG. 9.

The first metal electrode ME1 is located between the metal wire ML1 andthe metal wire ML2. The second metal electrode ME2 is located betweenthe metal wire ML2 and the metal wire ML3. The pedestal portion 100 ofthe metal wire ML2 is located between the first metal electrode ME1 andthe second metal electrode ME2. For example, the width W2 of thepedestal portion 100 is about 7.6 μm. Moreover, for example, the widthof the first metal electrode ME1 and the second metal electrode ME2,taken along the first direction X, is about 8.0 μm.

As will be discussed later, the through-holes CH11 and CH12 penetratethe insulating film 14, and a through-hole CH23 penetrates theinsulating film 15. The through-hole CH11 is formed in a positionoverlapping the first metal electrode ME1. The through-hole CH12 isformed in a position overlapping the second metal electrode ME2. Thethrough-hole CH23 is located between the first metal electrode ME1 andthe second metal electrode ME2, and is formed in a position overlappingthe pedestal portion 100. The width of the through-hole CH23 along thefirst direction X is about 4 μm.

The through-hole CH11 is located approximately at a center between themetal wire ML1 and the metal wire ML2 in plan view. The first metalelectrode ME1 has a width (first width) W11 on a side of the pedestalportion 100 with respect to the through-hole CH11, and a width (secondwidth) W12 on an opposite side to the pedestal portion 100 with respectto the through-hole CH11. The width W2 is greater than the width W1.That is, the first metal electrode ME1 is disposed closer to the metalwire ML1 as compared to the metal ire ML2.

The through-hole CH12 is located approximately at a center between themetal wires ML2 and ML3 in plan view. The second metal electrode ME2 hasa width (third width) W13 on a side of the pedestal portion 100 withrespect to the through-hole CH12 and a width (fourth width) W14 on anopposite side to the pedestal portion 100 with respect to thethrough-hole CH12. The width W14 is greater than the width W13. That is,the second metal electrode ME2 is disposed closer to the metal wire ML3as compared to the metal wire ML2. Therefore, the first metal electrodeME1 and the second metal electrode ME2 are disposed on one side so as tobe spaced from the pedestal portion 100.

The light-shielding layer BM is formed into a grid shape, and overlapseach of the scanning lines G1 to G3, the signal lines S1 to S3, themetal wires ML1 to ML3, the connection portions CN1 and CN2, the basesBS1 and BS2 and the drain electrodes DE1 and DE2, shown in FIG. 9. Thelight-shielding layer BM includes a first portion BM11 extending in thefirst direction X, and second portions BM21 to BM23 extending in thesecond direction Y. The first portion BM11 has a width W21 along in thesecond direction Y, and the second portions BM21 to BM23 each have awidth W22 along the first direction X. The width W21 is greater than thewidth W22. The first portion BM11 overlaps the pedestal portion 100, thefirst metal electrode ME1, the second metal electrode ME2 and thethrough-holes CH11, CH23 and CH12.

According to this embodiment, the first metal electrode ME1 and thesecond metal electrode ME2 are disposed on one side which is spacedapart from the metal wire ML2. With this configuration, the pedestalportion 100 can be disposed between the first metal electrode ME1 andthe second metal electrode ME2. In other words, the pedestal portion 100can be placed in the position overlapping the first portion BM11 of thelight-shielding layer BM. For example, when the pedestal portion 100 isdisposed in the position overlapping the second portion BM22 of thelight-shielding layer BM, light reflected in the pedestal portion 100may leak from both sides of the second portion BM22. In this embodiment,the pedestal portion 100 is located in the position overlapping thefirst portion BM1 having a width greater than that of the second portionBM22, the leakage of light from around the pedestal portion 100 can beinhibited. Therefore, the degrading of the contrast of the displaydevice caused by leakage of light can be suppressed. Thus, deteriorationin display quality can be suppressed.

FIG. 11 is a cross-sectional view of the first substrate SUB1 takenalong line E-F in FIG. 9. Note that in the first substrate SUB1 shown,the layers below the insulating film 13 and the alignment film AL1omitted from the illustration. Moreover, FIG. 11 also shows a plan viewof each of the first transparent electrode TE1, the second transparentelectrode TE2 and the bridge portion BR, which corresponds to thesection.

The first substrate SUB1 includes the drain electrodes DE1 and DE2, thesignal lines S1 to S3, the first metal electrode ME1, the second metalelectrode ME2, the first transparent electrode TE1, the secondtransparent electrode TE2, the metal wires ML1 to ML3, the insulatingfilms 13 to 16, the pixel electrodes PE1 and PE2 and the bridge portionBR.

The signal lines S1 to S3 and the drain electrodes DE1 and DE2 arelocated on the insulating film 13, and are covered by the insulatingfilm 14. The drain electrodes DE1 and DE2 are located in the same layeras that of the signal lines S1 to S3, and are formed of a materialidentical to that of the signal lines S1 to S3.

The insulating film 14 comprises the through-hole (first through-hole)CH11 which penetrates to the drain electrode DE1, and the through-hole(fifth through-hole) CH12 which penetrates to the drain electrode DE2.

The metal wires ML1 to ML3, the first metal electrode ME1 and the secondmetal electrode ME2 are located on the insulating film 14, and they arecovered by the insulating film 15. The first metal electrode ME1 is incontact with the drain electrode DE1 in the through-hole CH11.Similarly, the second metal electrode ME2 is in contact with the drainelectrode DE2 in the through-hole CH12. The first metal electrode ME1and the second metal electrode ME2 are located in the same layer as thatof the metal wires ML1 to ML3, and they are formed of a metal materialidentical to that of the metal wires ML1 to ML3. The metal wires ML1 toML3 are located immediately above the signal lines S1 to S3,respectively.

As shown in FIG. 10, the first metal electrode ME1 and the second metalelectrode ME2 are displaced to a side spaced away from the metal wireML2. The first metal electrode ME1, the second metal electrode ME2 andthe pedestal portion 100 are located in the same layer, and with such alayout, short-circuiting between the first metal electrode ME1 and thepedestal portion 100 and that between the second metal electrode ME2 andthe pedestal portion 100 can be suppressed.

The insulating film 14 is scraped when the metal wires ML1 to ML3, thefirst metal electrode ME1 and the second metal electrode ME2 aresubjected to dry etching. Therefore, a difference in level is created inthe insulating film 14 between a region where the film overlaps themetal wires ML1 to ML3, the first metal electrode ME1 and the secondmetal electrode ME2, and another region where it does not overlap these.

The insulating film 15 is located on the insulating film 14, andcomprises a through-hole (second through-hole) CH21 which penetrates tothe first metal electrode ME1, a through-hole (sixth through-hole) CH22which penetrates to the second metal electrode ME2, and a through-hole(fourth through-hole) CH23 which penetrates to the pedestal portion 100.The width of the through-hole CH21 is less than the width of thethrough-hole CH11, and the width of the through-hole CH22 is less thanthe width of the through-hole CH12.

The first transparent electrode TE1 and the second transparent electrodeTE2 and the bridge portion BR are located on the insulating film 15, andare covered by the insulating film 16. The first transparent electrodeTE1 is in contact with the first metal electrode ME1 in the through-holeCH21. Similarly, the second transparent electrode TE2 is in contact withthe second metal electrode ME2 in the through-hole CH22. The bridgeportion BR is in contact with the pedestal portion 100 in thethrough-hole CH23. The first transparent electrode TE1, the secondtransparent electrode TE2 and the bridge portion BR are located in thesame layer as that of the common electrodes CE1 and CE2 shown in FIG. 9,and are formed of a transparent conductive material as that of thecommon electrodes CE1 and CE2.

The through-hole CH21 is located approximately at a center between themetal wire ML1 and the metal wire ML2. The first transparent electrodeTE1 has a width (fifth width) W15 on a side of the bridge portion BRwith respect to the through-hole CH21 and a width (sixth width) W16 on aside opposite to the bridge portion BR with respect to the through-holeCH21. The width W16 is greater than the width W16. In other words, thefirst transparent electrode TE1 is displaced to a side spaced away fromthe bridge portion BR with respect to the through-hole CH21.

The through-hole CH22 is located approximately at a center between themetal wire ML2 and the metal wire ML3. The second transparent electrodeTE2 has a width (seventh width) W17 on a side of the bridge portion BRwith respect to the through-hole CH22, and a width (eighth width) W18 onan opposite side to the bridge portion BR with respect to thethrough-hole CH22. The width W18 is greater than the width W17. That is,the second transparent electrode TE2 is displaced to a side spaced awayfrom the bridge portion BR with respect to the through-hole CH22.

As described above, the first transparent electrode TE1 and the secondtransparent electrode TE2 are displaced to the side spaced away from thebridge portion BR. The first transparent electrode TE1, the secondtransparent electrode TE2 and the bridge portion BR are located in thesame layer, and with such a layout, short-circuiting between the firsttransparent electrode TE1 and the bridge portion BR and that between thesecond transparent electrode TE2 and the bridge portion BR can besuppressed.

The insulating film 16 is located on the insulating film 15, andcomprises a through-hole (third through-hole) CH31 which penetrates tothe first transparent electrode TE1, and a through-hole CH32 whichpenetrates to the second transparent electrode TE2. The through-holeCH31 is located on one side which is spaced away from the bridge portionBR with respect to the through-holes CH11 and CH21. The through-holeCH32 is located on one side which is spaced away from the bridge portionBR with respect to the through-holes CH12 and CH22.

The base BS1 of the pixel electrode PE1 and the base BS2 of the pixelelectrode PE2 are located on the insulating film 16, and are covered bythe alignment film AL1 (not shown). The pixel electrode PE1 is incontact with the first transparent electrode TE1 in the through-holeCH31. Similarly, the pixel electrode PE2 is in contact with the secondtransparent electrode TE2 in the through-hole CH32.

In the through-hole CH11, the stacked layer bodies SB1 and SB2 aredisposed. The stacked layer body SB1 includes the drain electrode DE1,the first metal electrode ME1, the first transparent electrode TE1 andthe pixel electrode PE1 staked one on another in this order. The stackedlayer body SB2 includes the drain electrode DE1, the first metalelectrode ME1, the first transparent electrode TE1, the insulating film16 and the pixel electrode PE1 stacked one on another in this order. Inthe example illustrated, the stacked layer body SB1 is located on a sideclose to the signal line S1 and the metal wire ML1, and the stackedlayer body SB2 is located on a side close to the signal line S2 and themetal wire ML2.

The insulating film 15 comprises an end portion 151E located between thefirst metal electrode ME1 and the first transparent electrode TE1 in aregion between a set of the signal line S1 and the metal wire ML1 andthe through-hole CH21. The pixel electrode PE1 is in contact with thefirst transparent electrode TE1 in a region immediately above the endportion 151E. Similarly, the insulating film 15 comprises an end portion152E located between the second metal electrode ME2 and the secondtransparent electrode TE2′in a region between a set of the signal lineS3 and the metal wire ML3 and the through-hole CH22. The pixel electrodePE2 is in contact with the second transparent electrode TE2 in a regionimmediately above the end portion 152E.

As described above, according to the first embodiment, a display devicewhich can suppress degradation of the image quality can be provided.

Next, a display device of the second embodiment will be explained indetail.

FIG. 12 is a cross-sectional view showing a display panel PNL takenalong line G-H in FIG. 2. FIG. 12 shows a non-display area NDA of thedisplay panel PNL.

The first substrate SUB1 comprises peripheral wires WR1 to WR3 in thenon-display area NDA. The peripheral wire WR1 is disposed on theinsulating film 12 and is covered by the insulating film 13. Theperipheral wire WR1 is disposed in the same layer as that of thescanning line, and is formed from a material identical to that of thescanning line. The peripheral wire WR2 is disposed on the insulatingfilm 13, and is covered by the insulating film 14. The peripheral wireWR2 is disposed in the same layer as that of the signal line and isformed from a material identical to that of the signal line. Theperipheral wire WR3 is disposed on the insulating film 16, and iscovered by the alignment film AL1. The peripheral wire WR3 is disposedin the same layer as that of the pixel electrode, and is formed from amaterial identical to that of the pixel electrode.

The first substrate SUB1 comprises a groove GR1 which penetrates theinsulating film 15 to the insulating film 14 in the non-display areaNDA. The groove GR1 is located on a side of the display area DA withrespect to the sealing material SE. Further, the first substrate SUB1comprises a groove GR2 which penetrates the insulating films 14 and 15to the insulating film 13 in the non-display area NDA. The groove GR2overlaps the sealing material SE.

The insulating film 16 is disposed on the insulating film 15, and alsoinside the groove GR1 and the groove GR2. The insulating film 16 is incontact with a side surface and a bottom surface of the groove GR1, andis in contact with a side surface of the groove GR2. A difference inlevel is created in the side surface of the groove GR2 by the insulatingfilms 14 and 15, and therefore the insulating film 16 easily adheres tothe side surface of the groove GR2.

The alignment film AL1 is disposed on the peripheral wire WR3 and alsoinside the groove GR1 and the groove GR2. In a region which overlaps thesealing material SE, the alignment film AL1 is not disposed on theinsulating film 15. Thus, the sealing material SE is in contact with theinsulating film 16. For example, if the alignment film AL1 is placedunder the sealing material SE, the adhesion strength between thealignment film AL1 and the insulating film 16 becomes weak, therebypossibly causing the peeling-off.

In this embodiment, the first substrate SUB1 comprises a groove GR1located on a side of the display area DA with respect to the sealingmaterial SE. With this configuration, even if the material of theprinted alignment film AL1 flows to the sealing material SE side, theflowing portion can be stopped by the groove GR1, and thus it ispossible to inhibit the flow from reaching the region which overlaps thesealing material SE. Moreover, even if the frame of the display deviceDSP can be narrowed, it is still possible to inhibit the material of thealignment film AL1 from flowing under the sealing material SE. Thus, thelowering of the adhesion strength between the first substrate SUB1 andthe second substrate SUB2 can be suppressed and the entering of moisturefrom the interface created by the peeling-off can be inhibited.

In order to stop the flow of the material alignment film AL1 within thegroove GR1, the depth of the groove GR1 should preferably be 0.2 μm ormore. In this embodiment, the depth of the groove GR1 is, for example,about 1.5 μm.

Further, in this embodiment, the first substrate SUB1 comprises twolayers, namely, the insulating films 14 and 15, each formed of anorganic insulating material. Therefore, of the two organic insulatingfilms, the groove GR1 is formed to penetrate the insulating film 15,which is closer to the liquid crystal layer LC. As compared to the casewhere a groove portion is formed by carrying out half exposure on oneorganic insulating film, in this embodiment, the side surface of thegroove GR1 can be formed steep to the bottom surface. Since the form ofthe side surface of the groove GR1 is steep, it is possible to inhibitthe material of the alignment film AL1 from flowing and running onto theregion under the sealing material SE. Moreover, in order to stop thesealing material SE more reliably by the groove GR1, the groove GR1 canbe deepened to such an extent that it does not penetrate the insulatingfilm 14.

Moreover, with the groove GR2, the entering path of moisture migratingfrom the outside of the display panel PNL through the insulating films14 and 15 can be blocked.

The light-shielding layer BM comprises a slit SL1 penetrating to thesecond insulating substrate 20. The entering path of moisture migratingin the light-shielding layer BM can be blocked by the slit SL1. Notethat the first substrate SUB1 comprises, in a position which overlapsthe slit SL1, a peripheral wire WR1, and with this configuration, theleakage of light from the slit SL1 can be inhibited.

The light-shielding layer BM comprises a slit SL2 in the region whichoverlaps the liquid crystal layer LC. With this configuration, themigration path of electric charge to the display area DA via thelight-shielding layer BM can be blocked in the slit SL2. Thus, it ispossible to inhibit static electricity form concentrating on the displayarea DA in the manufacturing process of the display panel PNL, and tosuppress damaging to the display panel PNL. Note that the firstsubstrate SUB1 comprises, in the position which overlaps the slit SL2, aperipheral wire WR2, and with this configuration, the leakage of lightfrom the slit SL2 can be suppressed. Moreover, the color filters CFR andCFB are disposed in the slit SL2 to overlap each other in the thirddirection Z. Thus, the leakage of light from the slit SL2 can besuppressed also against the light portion passing through around theperipheral wire WR2.

Spacers SP1 to SP4 are disposed on the second substrate SUB2 and projectout to a side of the first substrate SUB1. The spacers SP1 to SP4 areeach formed of, for example, a resin material. Further, a color filterCFB for height adjustment is provided in the position which overlaps thespacers SP1 and SP2. The liquid crystal layer LC is surrounded by thefirst substrate SUB1, the second substrate SUB2 and the sealing materialSE.

FIG. 13 is a plan view indicating positions of the grooves GR1 and GR2shown in FIG. 11.

The groove GR1 includes portions GR11 and GR12 extending in the seconddirection Y, and a portion GR13 extending in the first direction X. Theportions GR11 and GR12 are each connected to the portion GR13. In thisembodiment, the groove GR1 should preferably have a width of 100 μm. Thegroove GR1 is not formed between the display area DA and the mountingportion MA. On the mounting portion MA side, the distance from thedisplay area DA to the sealing material SE is great, the alignment filmAL1 does not reach the sealing material SE. With this configuration, onthe mounting portion MA side of the display area DA, the groove GR1 forstopping the alignment film AL1 need not be formed. The groove GR2includes portions GR21 and GR22 extending in the second direction Y, andportions GR23 and GR24 extending in the first direction X. The portionsGR21 and GR22 are connected to the portions GR23 and GR24, respectively.

FIG. 14 is a cross section showing a modified example of the displaypanel PNL according to the second embodiment shown in FIG. 12. Thestructure shown in FIG. 14 is different from that of FIG. 12 in that aperipheral electrode (first peripheral electrode) PRE1 is disposed underthe sealing material SE.

The peripheral electrode PRE1 is located between the sealing material SEand the insulating film 16. The peripheral electrode PRE1 is disposed inthe same layer as that of the peripheral wire WR3 and the pixelelectrode, and is formed from a material identical to that of thesemembers. With the peripheral electrode PRE1 disposed under the sealingmaterial SE, the adhesion strength of the sealing material SE can beenhanced, and the electric field from the peripheral wire WR1 can beshielded.

With this configuration, an advantageous effect similar to that of theexample shown in FIG. 12 can be obtained.

FIG. 15 is a cross section showing a modified example of the displaypanel PNL according to the second embodiment shown in FIG. 12. Thestructure shown in FIG. 15 is different from that of FIG. 12 in that theperipheral electrode (second peripheral electrode) PRE2 is disposed in aposition overlapping the sealing material SE.

The peripheral electrode PRE2 is disposed on the insulating film 15, andis covered by the insulating film 16. The peripheral electrode PRE2 isdisposed in the same layer as that of the common electrode, the firsttransparent electrode and the second transparent electrode, and isformed from a material identical to that of these members. With theperipheral electrode PRE2 disposed in the position overlapping thesealing material SE, the adhesion strength of the sealing material SEcan be enhanced and the electric field from the peripheral wire WR1 canbe shielded.

With this configuration, an advantageous effect similar to that of theexample shown in FIG. 12 can be obtained.

FIG. 16 is an enlarged view of a region I and a region J shown in FIG.13.

FIG. 16, part (a) shows an enlarged view of the region I. The portionGR11 of the groove GR1 has a width W31 along the first direction X. Thewidth W31 is about 150 μm. The portion GR12 shown in FIG. 13 has a widthsimilar to that of the portion GR11. The peripheral wire WR3 extends inthe second direction Y between the portion GR11 and the display area DA.

FIG. 16, part (b) shows an enlarged view of the region J. The portionGR13 has a width W32 along the second direction Y. The width W32 isgreater than the width W31. The width W32 is about 350 μm. Theperipheral wire WR3 extends in the first direction X between the portionGR13 and the display area DA.

As described above, according to the second embodiment, a display devicewhich can suppress degradation of the reliability can be provided.

Next, a display device according to a third embodiment will be explainedin detail.

FIG. 17 is a plan view showing a comparative example of the terminalportion T of the sensor wire L shown in FIG. 2.

A through-hole CH61 is located in a region overlapping the terminalportion T. The through-hole CH61 has a width W41 along the firstdirection X, and a width W42 along the second direction Y. For example,the width W41 is about 5 μm, and the width W42 is about 10 μm. Thethrough-hole CH61 comprises side surfaces SS1 to SS4.

FIG. 18 is a cross-sectional view of the first substrate SUB1 takenalong line K-M in FIG. 17.

The through-hole CH61 penetrates the insulating film 14 to theperipheral wire WR2. In the comparative example shown in FIG. 18, anangle θ11 between the side surface SS1 and the peripheral wire WR2 andan angle θ12 between the side surface SS2 and the peripheral wire WR2are greater than 90°. With this structure, the terminal portion T cannotfollow up the side surfaces SS1 and SS2, but is disconnected. Note thatthis is also the case for the side surfaces SS3 and SS4 shown in FIG.17.

FIG. 19 is a plan view showing a terminal portion T according to thethird embodiment. The structure shown in FIG. 19 is different from thatof FIG. 17 in that a through-hole (seventh through-hole) CH71 and athrough-hole (eighth through-hole) CH72 are different from that inwidth.

The through-holes CH71 and CH72 are located in a region overlapping theterminal portion T. The through-holes CH71 and CH72 each have a widthW51 along the first direction X and a width W52 along the seconddirection Y. The width W51 is less than the width W41 of thethrough-hole CH61 shown in FIG. 17, and the width W52 is less than thewidth W42. For example, the width W51 and the width W52 are each about3.5 μm. The through-hole CH71 comprises side surfaces SS11 to SS14, andthe through-hole CH72 comprises side surfaces SS15 to SS18.

In this embodiment, the width W51 is approximately equal to the width ofthe through-hole CH11 along the first direction X shown in FIG. 10, andthe width W52 is approximately equal to the width of the through-holeCH11 along the second direction Y.

FIG. 20 is a cross-sectional view of the first substrate SUB1 takenalong line N-O shown in FIG. 19.

The through-holes CH71 and CH72 penetrate the insulating film 14 to theperipheral wire (the first peripheral wire) WR2. In the thirdembodiment, the angle θ21 between the side surface SS11 and theperipheral wire WR2, the angle θ22 between the side 12 and theperipheral wire WR2, the angle θ23 between the side surface SS15 and theperipheral wire WR2, and the angle θ24 between the side surface SS16 andthe peripheral wire WR2 are 90° or less. With this configuration, theterminal portion T follows the side surface SS11, SS12, SS15 and SS16,and is electrically connected to the peripheral wire WR2 in thethrough-holes CH71 and CH72. Nota that this is also the case for theside surfaces SS13, SS14, SS17 and SS18 shown in FIG. 19.

Thus, the width of the through-holes CH71 and CH72 which overlap theterminal portion T is set equivalent to the width of the through-holeCH21 of the display area DA, and therefore disconnection of the terminalportion T can be inhibited.

In the example illustrated, two through-holes CH71 and CH72 are formedin the region which overlaps the terminal portion T, but the number ofthrough-holes may be one or three or more.

FIG. 21 is a plan view showing a comparative example of the peripheralwire WR3 in the region U shown in FIG. 16.

Through-holes CH81 and CH82 are located in the region which overlaps theperipheral wire WR3 and the metal electrode ME. The through-hole CH81comprises a width W61 along the first direction X, and a width W62 alongthe second direction Y. The through-hole CH82 comprises a width W71along the first direction X, and a width W72 along the second directionY. For example, the width W61 and the width W71 are approximately thesame and each are about 5 μm, and the width W62 and the width W72 areapproximately the same and each are about 10 μm. The through-hole CH81comprises side surfaces SS21 to SS24. The through-hole CH82 comprisesside surfaces SS25 to SS28.

FIG. 22 is a cross-sectional view of the first substrate SUB1 takenalong line P-Q shown in FIG. 21.

The metal electrode ME is located between the insulating film 14 and theinsulating film 15. The through-hole CH81 penetrates the insulating film14 to the peripheral wire WR2. The through-hole CH82 penetrates theinsulating film 15 to the metal electrode ME. In the through-hole CH81,an angle θ31 between the side surface SS21 and the peripheral wire WR2and an angle θ32 between the side surface SS22 and the peripheral wireWR2 are greater than 90°. Thus, the metal electrode ME cannot follow upthe side surfaces SS21 and SS22, but is disconnected. Note that this isalso the case for the side surfaces SS23 and SS24 shown in FIG. 21. Inthe through-hole CH82, an angle θ33 between the side surface SS25 andthe metal electrode ME and an angle θ34 between the side surface SS26and the metal electrode ME are greater than 90°. Thus, the peripheralwire WR3 can follow up the side surfaces SS25 and SS26, but isdisconnected. Note that this is also the case for the side surfaces SS27and SS28 shown in FIG. 21.

FIG. 23 is a plan view showing the region U of the peripheral wire WR3according to the third embodiment. The structure shown in FIG. 23 isdifferent from that of FIG. 21 in that a through-hole (ninththrough-hole) CH91, a through-hole CH92, a through-hole (tenththrough-hole) CH93 and through-hole CH94 are different from those inwidth.

The through-holes CH91 to CH94 are located in a region which overlapsthe peripheral wire (second peripheral wire) WR3 and the metal electrode(third metal electrode) ME. The through-holes CH91 and CH92 have a widthW81 along the first direction X, and a width W82 along the seconddirection Y. The width W81 is less than the width W61 of thethrough-hole CH81 shown in FIG. 21, and the width W82 is less than thewidth W62. For example, the width W81 and the width W82 each are about3.5 μm. The through-holes CH93 and CH94 have a width W91 along the firstdirection X, and a width W92 along the second direction Y. The width W91is less than the width W71 of the through-hole CH82 shown in FIG. 21,and the width W92 is less than the width W72. For example, the width W91and the width W92 each are about 4 μm. The through-hole CH91 comprisesside surfaces SS31 to SS34, and the through-hole CH92 comprises sidesurfaces SS35 to SS38. The through-hole CH93 comprises side surfacesSS41 to SS44, and the through-hole CH94 comprise side surfaces SS45 toSS48.

In this embodiment, the width W81 is approximately equal to the width ofthe through-hole CH11 along the first direction X shown in FIG. 10, andthe width W82 is approximately equal to the width of the through-holeCH11 along the second direction Y. Further, the width W91 isapproximately equal to the width of the through-hole CH21 along thefirst direction X shown in FIG. 11, and the width W92 is approximatelyequal to the width of the through-hole CH21 along the second directionY.

FIG. 24 is a cross-sectional view of the first substrate SUB1 takenalong line S-R shown in FIG. 23.

The through-holes CH91 and CH92 penetrate the insulating film 14 to theperipheral wire WR2. In the third embodiment, an angle θ41 between theside surface SS31 and the peripheral wire WR2, an angle θ42 between theside surface SS32 and the peripheral wire WR2, an angle θ43 between theside surface SS35 and the peripheral wire WR2, and an angle θ44 betweenthe side surface SS36 and the peripheral wire WR2 are 90° or less.Therefore, the metal electrode ME follows up the side surface SS31,SS32, SS35 and SS36, and is electrically connected to the peripheralwire WR2 in the through-holes CH91 and CH92. Note that this is also thecase for the side surface SS33, SS34, SS37, and SS38 shown in FIG. 23.

The through-holes CH93 and CH94 penetrate the insulating film 15 to themetal electrode ME. In the third embodiment, an angle θ51 between theside surface SS41 and the metal electrode ME, an angle θ52 between theside surface SS42 and the metal electrode ME, an angle θ53 between theside surface SS45 and the metal electrode ME, and an angle θ54 betweenthe side surface SS46 and the metal electrode ME are 90° or less. Thus,the peripheral wire WR3 follows up the side surfaces SS41, SS42, SS45and SS46, and is electrically connected to the metal electrode ME in thethrough-holes CH93 and CH94. Note that this is also the case for theside surface SS43, SS44, SS47 and SS48 shown in FIG. 23.

Thus, the width of the through-holes CH91 and CH92 which overlap theperipheral wire WR3 is set equal to the width of the through-hole CH11of the display area DA and the width of the through-holes CH93 and CH94is set equal to the width of the through-hole CH21 of the display areaDA, and therefore disconnection of the metal electrode ME and theperipheral wire W3 can be inhibited.

In the example illustrated, two through-holes CH91 and CH92 are formedto penetrate the insulating film 14 in the region which overlaps themetal electrode ME, but the number of through-holes which penetrate theinsulating film 14 may be one or three or more. Similarly, twothrough-holes CH93 and CH94 are formed to penetrate the insulating film15 in the region which overlaps the metal electrode ME, but the numberof through-holes which penetrate the insulating film 15 may be one orthree or more.

As described above, according to the third embodiment, a display devicewhich can suppress lowering of the production yield can be provided.

Note that the main structure disclosed in the first and thirdembodiments can be applied to spontaneous light-emitting display devicescomprising an organic electroluminescence display element or the like,electronic paper type display devices comprising an electrophoreticelement or the like, display devices adapting micro-electromechanicalsystems (MEMS), display device adapting electrochromism or the like.Moreover, the main structure disclosed in the second embodiment isapplicable to liquid crystal display devices.

Further, the expression “approximately equal” used in this specificationis used in consideration of the error which may occur in themanufacturing process. For example, it is assumed that the widths of thethrough-holes are those measured at a height location common to a heightfrom the lower bottom to the upper bottom of each through-hole.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising: a switching elementcomprising a first drain electrode; a first insulating film comprising afirst through-hole penetrating to the first drain electrode and formedof an organic insulating material; a first metal electrode in contactwith the first drain electrode in the first through-hole and formed of ametal material; a second insulating film located on the first insulatingfilm, comprising a second through-hole penetrating to the first metalelectrode, and formed of an organic insulating material; a firsttransparent electrode in contact with the first metal electrode in thesecond through-hole and formed of a transparent conductive material; athird insulating film located on the second insulating film, comprisinga third through-hole penetrating to the first transparent electrode andformed of an inorganic insulating material; a pixel electrode located onthe third insulating film and in contact with the first transparentelectrode in the third through-hole; and a metal wire located betweenthe first insulating film and the second insulating film and formed of amaterial identical to that of the first metal electrode.
 2. The displaydevice of claim 1, further comprising: a first common electrode and asecond common electrode, formed of a material identical to that of thefirst transparent electrode; and a bridge portion located between thefirst common electrode and the second common electrode, and electricallyconnecting the first common electrode and the second common electrode toeach other, wherein the metal wire comprises a line portion and apedestal portion which overlaps the bridge portion, the pedestal portionhas a width greater than a width of the line portion, the secondinsulating film comprises a fourth through-hole in a position whichoverlaps the pedestal portion, and the bridge portion is in contact withthe pedestal portion in the fourth through-hole.
 3. The display deviceof claim 2, further comprising: a light-shielding layer comprising afirst portion extending in a first direction and a second portionextending in a second direction which crosses the first direction,wherein the first portion has a width greater than that of the secondportion, and the pedestal portion and the fourth through-hole overlapthe first portion.
 4. The display device of claim 3, further comprising:a second drain electrode arranged along in the first direction of thefirst drain electrode; a second metal electrode in contact with thesecond drain electrode in a fifth through-hole which penetrates thefirst insulating film to the second drain electrode; and a secondtransparent electrode in contact with the second metal electrode in asixth through-hole which penetrates the second insulating film to thesecond metal electrode, wherein the pedestal portion and the fourththrough-hole are located between the first metal electrode and thesecond metal electrode.
 5. The display device of claim 4, wherein thefirst common electrode and the second common electrode are arrangedalong the second direction, the first transparent electrode and thesecond transparent electrode are arranged along the first directionbetween the first common electrode and the second common electrode, andthe bridge portion is located between the first transparent electrodeand the second transparent electrode.
 6. The display device of claim 4,wherein the first metal electrode has a first width on a side of thepedestal portion with respect to the first through-hole, and a secondwidth on an opposite side to the pedestal portion with respect to thefirst through-hole, the second width is larger than the first width, thesecond metal electrode has a third width on a side of the pedestalportion with respect to the fifth through-hole, and a fourth width on anopposite side to the pedestal portion with respect to the fifththrough-hole, and the fourth width is greater than the third width. 7.The display device of claim 4, wherein the first transparent electrodehas a fifth width on a side of the bridge portion with respect to thesecond through-hole, and a sixth width on an opposite side to the bridgeportion with respect to the second through-hole, the sixth width islarger than the fifth width, the second transparent electrode has aseventh width on a side of the bridge portion with respect to the sixththrough-hole, and an eighth width on an opposite side to the bridgeportion with respect to the sixth through-hole, the eighth width islarger than the seventh width.
 8. The display device of claim 1, whereinthe first drain electrode, the first metal electrode, the firsttransparent electrode and the pixel electrode are stacked one on anotherin this order in the first through-hole, thus forming a first stackedlayer, and the first drain electrode, the first metal electrode, thefirst transparent electrode, the third insulating film and the pixelelectrode are stacked one on another in this order in the firstthrough-hole, thus forming a second stacked layer.
 9. The display deviceof claim 1, wherein the second insulating film comprises an end portionlocated between the first metal electrode and the first transparentelectrode, and the pixel electrode is in contact with the firsttransparent electrode immediately above the end portion.
 10. The displaydevice of claim 2, wherein the first common electrode and the secondcommon electrode form a sensor electrode to which touch drive voltage isapplied in a touch sensing mode.
 11. The display device of claim 1,further comprising: a signal line electrically connected to theswitching element and formed of a material identical to that of thefirst drain electrode, wherein the metal wire is located immediatelyabove the signal line.
 12. The display device of claim 1, furthercomprising: a display area and a non-display area surrounding thedisplay area; a first substrate including the first metal electrode, thefirst transparent electrode, the metal wire, the first insulating film,the second insulating film, the third insulating film and the pixelelectrode, and comprising an alignment film which covers the pixelelectrode and the third insulating film, and a groove portion whichpenetrates the second insulating film to the first insulating film inthe non-display area; a second substrate opposing the first substrate; asealing material which adheres the first substrate and the secondsubstrate; and a liquid crystal layer surrounded by the first substrate,the second substrate and the sealing material, wherein the grooveportion is located on a side of the display area with respect to thesealing material.
 13. The display device of claim 12, wherein the grooveportion has a width of 100 um or more.
 14. The display device of claim12, wherein the sealing material is in contact with the third insulatingfilm.
 15. The display device of claim 12, further comprising: a firstperipheral electrode located between the sealing material and the thirdinsulating film, and formed of a material identical to that of the pixelelectrode.
 16. The display device of claim 12, further comprising asecond peripheral electrode located between the second insulating filmand the third insulating film in a region which overlaps the sealingmaterial, and formed of a material identical to that of the firsttransparent electrode.
 17. The display device of claim 1, furthercomprising: a display area and a non-display area surrounding thedisplay area; and a first peripheral wire located in the non-displayarea, wherein the metal wire comprises a terminal portion in contactwith the first peripheral wire in a seventh through-hole that penetratesthe first insulating film to the first peripheral wire, the sevenththrough-hole has a width along a first direction, which is substantiallya same as a width of the first through-hole along the first direction,and the seventh through-hole has a width along a second directioncrossing the first direction, which is substantially a same as a widthof the first through-hole along the second direction.
 18. The displaydevice of claim 17, wherein the first insulating film comprises aneighth through-hole which penetrates to the first peripheral wire in aposition which overlaps the terminal portion, the terminal portion is incontact with the first peripheral wire in the eighth through-hole, theeighth through-hole has a width along the first direction, which issubstantially a same as a width of the seventh through-hole along thefirst direction, and the eighth through-hole has a width along thesecond direction, which is substantially a same as a width of theseventh through-hole along the second direction.
 19. The display deviceof claim 1, further comprising: a display area and a non-display areasurrounding the display area; a first peripheral wire located in thenon-display area; a second peripheral wire located on the thirdinsulating film and overlapping the first peripheral wire; and a thirdmetal electrode disposed between the first insulating film and thesecond insulating film in a position which overlaps the first peripheralwire and the second peripheral wire, wherein the third metal electrodeis in contact with the first peripheral wire in the ninth through-holewhich penetrates the first insulating film to the first peripheral wire,the ninth through-hole has a width along the first direction, which issubstantially a same as a width of the first through-hole along thefirst direction, and the ninth through-hole has a width along a seconddirection crossing the first direction, which is substantially a same asa width of the first through-hole along the second direction.
 20. Thedisplay device of claim 19, wherein the second peripheral wire is incontact with the third metal electrode in a tenth through-hole thatpenetrates the second insulating film to the third metal electrode, thetenth through-hole has a width along the first direction, which issubstantially a same as a width of the second through-hole along thefirst direction, and the tenth through-hole has a width along the seconddirection, which is substantially a same as a width of the secondthrough-hole along the second direction.